Whistleblowers get new protection against discrimination by the NHS under new laws coming into force on 23 May 2018 in England, Wales and Scotland (see Employment Rights Act 1996 (NHS Recruitment-Protected Disclosure) Regulations 2018 SI 2018/579). From then it will be unlawful for NHS employers (well most of them) to refuse to take on an applicant for work or otherwise treat them less favourably than other applicants because they blew the whistle. This is whether the applicant is applying from inside or outside the NHS.
See http://www.breakinglaw.co.uk/2017/05/power-to-whistleblowers.html. for more whistleblowing info.
If the new law is broken then the applicant can apply to an employment tribunal or a civil court for compensation but not both unless the civil court proceedings are restricted to a claim for an injunction to prevent the NHS from further discrimination.